After its lackluster debut last Monday, there has been a series of encouraging news for Fox’s Terra Nova in the past 24 hours. First, the prehistoric drama yesterday rose to the top spot in 18-49 among all new drama series premieres in Live+3 ratings. Then the data from the international markets came in, showing a strong launch for Terra Nova in almost every territory. In Canada, the two-hour opener drew 1.4 million viewers on CityTV to become the most-watched drama in the network’s history. And then the first ratings for last night were released this morning with more good news for the rookie drama: In its second outing on Fox, Terra Nova (3.0/8) matched the fast national for its two-hour premiere despite airing from 8-9 PM vs. 8-10 PM last week. (Last week, the premiere was adjusted up in the finals, which will probably happen again today, so the 100% hold will likely carry on in the final ratings.) UPDATE 9:25 AM: Fox just released final numbers for Terra Nova, and it indeed rose to a 3.1 rating. This is the best Week 1-to-Week 2 retention for a new series this fall. At 9 PM, veteran House (3.9/9) was down a modest 7% from last fall when it aired in the more challenging 8 PM hour.

Another strong showing for CBS’ Monday comedy block: How I Met Your Mother (4.5/12) was up a tenth from last week’s fast national rating (even with the final but will probably be adjusted up again), 2 Broke Girls (4.4/11) was down a tenth, Two And A Half Men (6.1/14) was down 15% (18% from the final), and Mike & Molly (4.3/10) didn’t get much of a boost from star Melissa McCarthy’s stint on Saturday Night Live — down 12% (10% from the final as it was adjusted down). With two double-digit week-to-week declines, Two And A Half Men is now close to Charlie Sheen levels. Still, the revamped veteran seems to have reinvigorated CBS’ Monday lineup, helped by strong new addition 2 Broke Girls, the highest-rated new series this season. When was the last time we’ve seen four back-to-back series on a network logging fast national 18-49 ratings over 4? And while Men and 2 Broke Girl understandably take the spotlight, for me the overachiever of the comedy block this year is HIMYM, which continues to impress. After posting series highs for its seventh(?!)-season premiere, the series barely dropped in Week 2 and is gaining ground again in Week 3. At 10 PM, Hawaii Five-0 (3.2/8) was flat. CBS (4.3/10, 12.4 million) swept every half-hour of primetime in both 18-49 for a decisive nightly victory.

Whether it is the current cast not connecting with viewers or the series’ age starting to show, ABC’s Dancing With the Stars (3.1/7) is fading this fall. It was down another 6% last night to post the reality veteran’s lowest-rated performance show ever. At 10 PM, Castle (2.6/6) was down 7%. ABC (2.9/7, 14.9 million) still won the night in total viewers while finishing third in 18-49.

NBC’s The Sing-Off (1.8/4) was up a tenth but its lead-out, freshman The Playboy Club (1.2/3), didn’t show desperately needed improvement, down a tenth from last week and pretty much sealing its fate as one of the season’s first casualties. Rumors are flying that this may have been the last regular airing of the series, with Brian Willams’ primetime newsmagazine fast-tracked for a late October launch. NBC (1.6/4, 4.4 million) finished a distant fifth for the night in 18-49 behind CBS, Fox, ABC and Univision (2.7/7, 6.1 million)

In Week 2, CW’s Hart Of Dixie (0.9/2 in 18-34, 0.8/2 in 18-49) was even in 18-49 and up 13% in 18-34 from its premiere.